Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity

TL;DR

This paper demonstrates that spin-spin interactions exist in gauge theory of gravity through gravitomagnetic fields, violate the weak equivalence principle, and proposes an experiment to detect these effects.

Contribution

It reveals the existence of spin-spin interactions in gauge gravity theory and discusses their implications for the weak equivalence principle and experimental detection.

Findings

Spin-spin interactions exist in gauge gravity theory.

These interactions violate the weak equivalence principle.

An experiment is proposed to detect the violation effects.

Abstract

For a long time, it is generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interactions will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.